The Prime Minister received an incredible cultural welcome at the airport and at Atu Pare Marae - with music, dancing and even a flax carpet.

"It might be my first visit here, but it certainly won't be my last," she told the crowd.

It's a first visit that pension-aged Cook Islanders won't forget, as Ms Ardern announced full pension portability would be introduced "no later than January 2019".

It means the New Zealand pension will be available for more Pacific retirees.

Currently, those from the Cook Islands, Niue, and Tokelau are entitled to the New Zealand pension if they've lived and worked in New Zealand for 10 years after the age of 20, and spent another five years doing so once they have turned 50.

The changes announced today will see that last requirement scrapped.

Deputy Prime Minister Winston Peters says the existing restrictions were unfair because they didn't apply to immigrants from elsewhere in the world.

"In our country over 87,000 people who've come in the last 15 years to get a full pension after just 10 years," he says. "Now see the inequity of that."

It means an additional 200 people from the islands will be eligible or the pension, which Ms Ardrn says will cost $3.5 million.

"It will have a huge effect for Tokelau, Niue, and the Cook Islands," she says.

There's still the problem of superannuation fund deductions.

The New Zealand Government reduces the pension payment amounts for those who have a super fund in the Pacific, which is comparable to New Zealanders having their pensions cut just because they're in KiwiSaver.

The changes have been a long time coming, with Cook Islands Prime Minister Henry Puna blaming one thing - the National Party.

Mr Peters backed the sentiment entirely, even if the pension problem was around when he was last Foreign Minister in 2005.